|
| 1 | +// Copyright 2013 The Flutter Authors. All rights reserved. |
| 2 | +// Use of this source code is governed by a BSD-style license that can be |
| 3 | +// found in the LICENSE file. |
| 4 | + |
| 5 | +#include "flutter/fml/backtrace.h" |
| 6 | + |
| 7 | +#include <cxxabi.h> |
| 8 | +#include <sstream> |
| 9 | + |
| 10 | +#include <dlfcn.h> |
| 11 | +#include <execinfo.h> |
| 12 | +#include <signal.h> |
| 13 | + |
| 14 | +#include "flutter/fml/logging.h" |
| 15 | + |
| 16 | +namespace fml { |
| 17 | + |
| 18 | +static std::string kKUnknownFrameName = "Unknown"; |
| 19 | + |
| 20 | +static std::string DemangleSymbolName(const std::string& mangled) { |
| 21 | + if (mangled == kKUnknownFrameName) { |
| 22 | + return kKUnknownFrameName; |
| 23 | + } |
| 24 | + |
| 25 | + int status = 0; |
| 26 | + size_t length = 0; |
| 27 | + char* demangled = __cxxabiv1::__cxa_demangle( |
| 28 | + mangled.data(), // mangled name |
| 29 | + nullptr, // output buffer (malloc-ed if nullptr) |
| 30 | + &length, // demangled length |
| 31 | + &status); |
| 32 | + |
| 33 | + if (demangled == nullptr || status != 0) { |
| 34 | + return mangled; |
| 35 | + } |
| 36 | + |
| 37 | + auto demangled_string = std::string{demangled, length}; |
| 38 | + free(demangled); |
| 39 | + return demangled_string; |
| 40 | +} |
| 41 | + |
| 42 | +static std::string GetSymbolName(void* symbol) { |
| 43 | + Dl_info info = {}; |
| 44 | + |
| 45 | + if (::dladdr(symbol, &info) == 0) { |
| 46 | + return kKUnknownFrameName; |
| 47 | + } |
| 48 | + |
| 49 | + return DemangleSymbolName({info.dli_sname}); |
| 50 | +} |
| 51 | + |
| 52 | +std::string BacktraceHere(size_t offset) { |
| 53 | + constexpr size_t kMaxFrames = 256; |
| 54 | + void* symbols[kMaxFrames]; |
| 55 | + const auto available_frames = ::backtrace(symbols, kMaxFrames); |
| 56 | + if (available_frames <= 0) { |
| 57 | + return ""; |
| 58 | + } |
| 59 | + |
| 60 | + std::stringstream stream; |
| 61 | + for (int i = 1 + offset; i < available_frames; ++i) { |
| 62 | + stream << "Frame " << i - 1 - offset << ": " << symbols[i] << " " |
| 63 | + << GetSymbolName(symbols[i]) << std::endl; |
| 64 | + } |
| 65 | + return stream.str(); |
| 66 | +} |
| 67 | + |
| 68 | +static size_t kKnownSignalHandlers[] = { |
| 69 | + SIGABRT, // abort program |
| 70 | + SIGFPE, // floating-point exception |
| 71 | + SIGBUS, // bus error |
| 72 | + SIGSEGV, // segmentation violation |
| 73 | + SIGSYS, // non-existent system call invoked |
| 74 | + SIGPIPE, // write on a pipe with no reader |
| 75 | + SIGALRM, // real-time timer expired |
| 76 | + SIGTERM, // software termination signal |
| 77 | +}; |
| 78 | + |
| 79 | +static std::string SignalNameToString(int signal) { |
| 80 | + switch (signal) { |
| 81 | + case SIGABRT: |
| 82 | + return "SIGABRT"; |
| 83 | + case SIGFPE: |
| 84 | + return "SIGFPE"; |
| 85 | + case SIGBUS: |
| 86 | + return "SIGBUS"; |
| 87 | + case SIGSEGV: |
| 88 | + return "SIGSEGV"; |
| 89 | + case SIGSYS: |
| 90 | + return "SIGSYS"; |
| 91 | + case SIGPIPE: |
| 92 | + return "SIGPIPE"; |
| 93 | + case SIGALRM: |
| 94 | + return "SIGALRM"; |
| 95 | + case SIGTERM: |
| 96 | + return "SIGTERM"; |
| 97 | + }; |
| 98 | + return std::to_string(signal); |
| 99 | +} |
| 100 | + |
| 101 | +static void ToggleSignalHandlers(bool set); |
| 102 | + |
| 103 | +static void SignalHandler(int signal) { |
| 104 | + // We are a crash signal handler. This can only happen once. Since we don't |
| 105 | + // want to catch crashes while we are generating the crash reports, disable |
| 106 | + // all set signal handlers to their default values before reporting the crash |
| 107 | + // and re-raising the signal. |
| 108 | + ToggleSignalHandlers(false); |
| 109 | + |
| 110 | + FML_LOG(ERROR) << "Caught signal " << SignalNameToString(signal) |
| 111 | + << " during program execution." << std::endl |
| 112 | + << BacktraceHere(3); |
| 113 | + |
| 114 | + ::raise(signal); |
| 115 | +} |
| 116 | + |
| 117 | +static void ToggleSignalHandlers(bool set) { |
| 118 | + for (size_t i = 0; i < sizeof(kKnownSignalHandlers) / sizeof(size_t); ++i) { |
| 119 | + auto signal_name = kKnownSignalHandlers[i]; |
| 120 | + auto handler = set ? &SignalHandler : SIG_DFL; |
| 121 | + |
| 122 | + if (::signal(signal_name, handler) == SIG_ERR) { |
| 123 | + FML_LOG(ERROR) << "Could not attach signal handler for " << signal_name; |
| 124 | + } |
| 125 | + } |
| 126 | +} |
| 127 | + |
| 128 | +void InstallCrashHandler() { |
| 129 | + ToggleSignalHandlers(true); |
| 130 | +} |
| 131 | + |
| 132 | +bool IsCrashHandlingSupported() { |
| 133 | + return true; |
| 134 | +} |
| 135 | + |
| 136 | +} // namespace fml |
0 commit comments